Ultra-conductive metals refer to alloys or composites which exhibit greater electrical conductivity than the pure metal from which the ultra-conductive metal is formed. Ultra-conductive metals are produced through the incorporation of certain, highly conductive, additives into a pure metal to form an alloy or composite with improved electrical conductivity. For example, ultra-conductive copper can be formed through the incorporation of highly conductive nano-carbon particles, such as carbon nanotubes and/or graphene, into high purity copper. Known ultra-conductive metals have required the inclusion of large quantities of such highly conductive additives to significantly boost the electrical conductivity of the pure metal.
PCT Patent App. Pub. No. WO 2018/064137 describes a method of forming a metal-graphene composite including coating metal components (10) with graphene (14) to form graphene-coated metal components, combining a plurality of the graphene-coated metal components to form a precursor workpiece (26), and working the precursor workpiece (26) into a bulk form (30) to form the metal-graphene composite. A metal-graphene composite includes graphene (14) in a metal matrix wherein the graphene (14) is single-atomic layer or multi-layer graphene (14) distributed throughout the metal matrix and primarily (but not exclusively) oriented with a plane horizontal to an axial direction of the metal-graphene composite.
U.S. Patent App. Pub. No. US 2016/0168693 A1 describes a method of tailoring an amount of graphene in an electrically conductive structure, includes arranging a substrate material in a plurality of strands and arranging at least one graphene layer coated circumferentially on one or more of the strands of the plurality of strands, the graphene layer being a single atom-thick layer of carbon atoms arranged in a hexagonal pattern, the substrate material and the at least one graphene layer having an axial direction. A first cross-section taken along the axial direction of the substrate and the at least one graphene layer includes a plurality of layers of the substrate material and at least one internal layer of the graphene alternatively disposed between the plurality of layers of the substrate material.